1. Field of the Invention
The present invention relates to an image processing apparatus and an image processing method, and more particularly to an image processing technique for generating edge information, which is adaptable to rendering processing or the like.
2. Description of the Related Art
Conventionally, a rendering method for extracting contour information (also referred to as edge information) relating to a graphic from coordinate information relating to the graphic to draw the graphic and forming an image based on the contour information has generally been used widely (e.g., Japanese Patent Application Laid-Open Nos. 04-170686, 08-72317, 2005-267290, and 2007-122188). While the contour information is represented by a straight line, a digital differential analyzer (DDA) algorithm has been known as a method for representing the straight line (David Rogers, “Procedural Elements for Computer Graphics”, McGraw-Hill Education).
An important requirement is to enable drawing processing to be executed at high speed in rendering processing. However, a period of time consumed to actually perform the rendering processing changes depending on the type of graphic and the number of graphics. Therefore, it is difficult to always carry out rendering fast. In conventional rendering processing, a procedure (algorithm) for performing data processing regardless of a graphic type is fixed. This is insufficient in terms of increasing the speed of the rendering processing.